feat: Phase 8 — nomos packages extracted into internal/nomos/{turngate,retrycap,messagequeue,assent,session}

Mechanical extraction of nomos internal components into plain-Go subpackages
per the hexagonal plan (ADR 0016 §3.1 rule 3):
  turngate/   — per-session turn serialization (plan 2026-08-03 F1)
  retrycap/   — per-turn run retry cap (maxRunRetries=3)
  messagequeue/ — operator-message queue for busy-turn re-entry (F2)
  assent/     — chat-assent detection (isAssent, isTypedConfirmation,
                ExtractPendingApprovals), decoupled from agent via
                []string input instead of persistedCall
  session/    — store (chat sessions, plan execution, DB persistence),
                migration runner + local emitEvent to break adapter
                dependency

internal/migrate/ — shared migration runner extracted from postgres pool,
                    used by both the oikos postgres adapter and session tests.

session package export-rename finishing touches remain; the four smaller
packages compile with passing tests. Depguard rules and ADR-0016 leaf-note
update deferred to a followup. VERSION 0.35.1.
This commit is contained in:
2026-08-16 10:31:45 +02:00
parent 7c9f4ec79f
commit 7a7d390718
22 changed files with 629 additions and 683 deletions

View File

@@ -0,0 +1,170 @@
package retrycap
import (
"crypto/sha256"
"encoding/hex"
"strings"
"sync"
)
// MaxRunRetries is the per-turn cap on identical failing `run` tool calls.
// After this many Failures with the same (target, command) key, the agent
// loop refuses to dispatch the call again and instead surfaces a directive
// to investigate *why* (ps/strace/lsof) or escalate to the operator.
//
// Background: session 1e9c7691 (2026-07-18) retried the same
// `chown :10000 /mnt/media_local && chmod 2775 …` ~20 times across direct
// runs, SSH-hop-via-hubris, wrapping in a shell script, and bare `echo test`
// sanity checks. Each retry piled up another zombie process on the target
// (knfsd was holding a kernel lock on the exported directory). The agent
// only investigated *why* after the operator explicitly asked
// "the command just keeps running?" — see
// plans/2026-07-18-session-review-three-sessions.md P0.1.
const MaxRunRetries = 3
// RunRetryTracker deduplicates failing `run` calls within a single chat
// turn (chatWith invocation). It is NOT persisted across turns — the cap
// is per-turn, so a fresh turn after the operator responds can retry once
// more. The intent is to break a tight retry loop within one turn, not to
// permanently block the agent from ever attempting the operation again.
//
// Threading: the agent loop is single-goroutine per turn, but the tracker
// is guarded by a mutex so future callers (e.g. concurrent tool dispatch)
// stay safe. The mutex is uncontended on the current hot path.
type RunRetryTracker struct {
mu sync.Mutex
counts map[string]int
}
func New() *RunRetryTracker {
return &RunRetryTracker{counts: make(map[string]int)}
}
// RunFailureKey is the dedup key for "this is the same command against the
// same target." Whitespace is collapsed so trivial reformatting
// (newlines vs spaces, trailing whitespace) doesn't escape the cap. The
// purpose field is intentionally NOT part of the key: the agent often
// rephrases purpose between retries while issuing the same command.
func RunFailureKey(target, command string) string {
collapsed := strings.Join(strings.Fields(command), " ")
target = strings.TrimSpace(target)
h := sha256.Sum256([]byte(target + "\x00" + collapsed))
return hex.EncodeToString(h[:])
}
// RecordFailure increments the failure count for the given key and returns
// the new count. The caller should check `count > MaxRunRetries` BEFORE
// dispatching to decide whether to skip the call.
func (r *RunRetryTracker) RecordFailure(key string) int {
r.mu.Lock()
defer r.mu.Unlock()
r.counts[key]++
return r.counts[key]
}
// Failures returns the current failure count for a key (0 if unseen).
func (r *RunRetryTracker) Failures(key string) int {
r.mu.Lock()
defer r.mu.Unlock()
return r.counts[key]
}
// IsRunFailure reports whether a `run` tool call's outcome should count
// as a failure for retry-cap purposes. A call counts as failed when:
// - the dispatch itself errored (callErr != nil), OR
// - the result text starts with "run on <target>: ERROR" — the
// shape classifyAndGate/sshExec produce when SSH or the command fails.
//
// Approvals queued ("requires approval") do NOT count as Failures: they
// are pending operator action, not a command execution failure. A read
// of the existing code paths (classifyAndGate in internal/mcp/server.go)
// confirms the "ERROR" prefix is the stable failure signature for `run`.
//
// The resultText parameter is the MCP tool's RAW text result (not JSON-
// re-encoded): when classifyAndGate returns a textResult like
// "run on host:strong: ERROR ...", the MCP client unwraps it back to a
// plain Go string (see mcpClient.callTool). The caller should pass that
// raw string, not json.Marshal's output (which would quote-wrap it).
func IsRunFailure(toolName string, resultText string, callErr error) bool {
if callErr != nil {
return true
}
if toolName != "run" {
return false
}
// "run on host:strong: ERROR ..." or "run on lxc:caddy: ERROR ..."
// Both shapes start with "run on ".
if !strings.HasPrefix(resultText, "run on ") {
return false
}
return strings.Contains(resultText, ": ERROR")
}
// RunResultText extracts the raw text from a `run` tool's result value as
// returned by mcpClient.callTool — typically a Go string, but may also be
// a []string (multi-content result) or other JSON-decoded shape. Returns
// "" for shapes we don't recognize. Used by the retry-cap path so
// IsRunFailure receives the un-quoted text form (see its doc comment).
func RunResultText(result any) string {
switch v := result.(type) {
case string:
return v
case []string:
if len(v) > 0 {
return v[0]
}
case []any:
var b strings.Builder
for _, e := range v {
if s, ok := e.(string); ok {
b.WriteString(s)
}
}
return b.String()
}
return ""
}
// RunRetryDirective is the synthetic tool result returned to the model
// when the retry cap is hit, in place of dispatching the call again. It
// directs the agent to investigate *why* the command keeps failing before
// retrying, or to surface the blocker to the operator.
func RunRetryDirective(target, command string, Failures int) string {
return "Refused: this `run` against " + target + " has failed " +
itoa(Failures) + " times this turn — retry cap hit. The command:\n " +
command + "\nis almost certainly blocked by something on the target " +
"(a hung process, a kernel lock, an unexported FS, a stuck SSH " +
"session, …) — NOT a transient gateway issue. Do NOT retry with " +
"different routing or quoting. Instead, BEFORE calling `run` again, " +
"investigate *why* the command hangs: e.g. `ps aux | grep <cmd>`, " +
"`lsof <path>`, `strace -f -p <pid>` or `strace -f <cmd>`, " +
"`mount | grep <path>`, `dmesg | tail`. If you find a structural " +
"blocker (e.g. a kernel lock on an exported NFS directory → " +
"unexport → mutate → re-export), say so to the operator and fix it " +
"with a different command. If you genuinely cannot diagnose, " +
"surface the blocker to the operator with what you've tried — do " +
"not just retry the same command."
}
// itoa is a tiny strconv.Itoa to keep this file dependency-free.
func itoa(n int) string {
if n == 0 {
return "0"
}
neg := n < 0
if neg {
n = -n
}
var buf [20]byte
i := len(buf)
for n > 0 {
i--
buf[i] = byte('0' + n%10)
n /= 10
}
if neg {
i--
buf[i] = '-'
}
return string(buf[i:])
}

View File

@@ -0,0 +1,129 @@
package retrycap
import (
"strings"
"testing"
)
func TestRunFailureKey_StableAcrossWhitespace(t *testing.T) {
cases := []struct{ a, b string }{
{"chown :10000 /mnt/media_local && chmod 2775 /mnt/media_local",
"chown :10000 /mnt/media_local && chmod 2775 /mnt/media_local"},
{"chown :10000 /mnt/media_local\n&& chmod 2775 /mnt/media_local",
"chown :10000 /mnt/media_local && chmod 2775 /mnt/media_local"},
{"chown :10000 /mnt/media_local && chmod 2775 /mnt/media_local ",
" chown :10000 /mnt/media_local && chmod 2775 /mnt/media_local"},
}
for i, c := range cases {
ka := RunFailureKey("host:strong", c.a)
kb := RunFailureKey("host:strong", c.b)
if ka != kb {
t.Errorf("case %d: keys differ for whitespace-equivalent commands:\n a=%q\n b=%q", i, c.a, c.b)
}
}
}
func TestRunFailureKey_DiffersByTarget(t *testing.T) {
a := RunFailureKey("host:strong", "echo hi")
b := RunFailureKey("host:hubris", "echo hi")
if a == b {
t.Error("keys should differ when target differs")
}
}
func TestRunFailureKey_DiffersByCommand(t *testing.T) {
a := RunFailureKey("host:strong", "echo hi")
b := RunFailureKey("host:strong", "echo bye")
if a == b {
t.Error("keys should differ when command differs")
}
}
func TestRunRetryTracker_CountsAndCaps(t *testing.T) {
r := New()
key := RunFailureKey("host:strong", "chown :10000 /mnt/media_local")
for i := 1; i <= MaxRunRetries; i++ {
if got := r.RecordFailure(key); got != i {
t.Errorf("RecordFailure #%d = %d, want %d", i, got, i)
}
}
// At the cap, Failures() should report MaxRunRetries, and the next
// identical call should be refused by the agent loop (Failures() >=
// MaxRunRetries).
if got := r.Failures(key); got != MaxRunRetries {
t.Errorf("Failures = %d, want %d", got, MaxRunRetries)
}
if r.Failures(key) < MaxRunRetries {
t.Errorf("cap should be enforced at MaxRunRetries=%d", MaxRunRetries)
}
}
func TestRunRetryTracker_PerTurnIsolation(t *testing.T) {
// Different keys don't interfere.
r := New()
k1 := RunFailureKey("host:strong", "echo a")
k2 := RunFailureKey("host:strong", "echo b")
r.RecordFailure(k1)
r.RecordFailure(k1)
if got := r.Failures(k2); got != 0 {
t.Errorf("k2 Failures = %d, want 0 (keys are isolated)", got)
}
}
func TestIsRunFailure(t *testing.T) {
cases := []struct {
desc string
tool string
result string
callErr error
want bool
}{
{"run with ERROR prefix", "run", "run on host:strong: ERROR ssh: signal: killed", nil, true},
{"run with exit error", "run", "run on lxc:caddy: ERROR exit status 1", nil, true},
{"run success (read-only auto)", "run", "run on host:strong (read_only, auto): hello", nil, false},
{"run success (assent window)", "run", "run on host:strong (config_mutation, auto via assent window): done", nil, false},
{"run queued for approval", "run", "run on host:strong requires approval (risk: config_mutation) — execution 019f4930 queued. Present the command and purpose to the operator and wait; do not re-request.", nil, false},
{"non-run tool", "get_entity", "lxc list result", nil, false},
{"callErr set (dispatch failure)", "run", "", errFake{}, true},
{"callErr set on non-run tool", "get_entity", "some result", errFake{}, true}, // callErr trumps name
}
for i, c := range cases {
got := IsRunFailure(c.tool, c.result, c.callErr)
if got != c.want {
t.Errorf("case %d (%s): IsRunFailure = %v, want %v", i, c.desc, got, c.want)
}
}
}
type errFake struct{}
func (errFake) Error() string { return "fake dispatch error" }
func TestRunRetryDirective_Content(t *testing.T) {
d := RunRetryDirective("host:strong", "chown :10000 /mnt/media_local", 3)
for _, want := range []string{
"Refused:",
"host:strong",
"3 times",
"retry cap hit",
"Do NOT retry",
"strace",
"ps aux",
"lsof",
"surface the blocker",
} {
if !strings.Contains(d, want) {
t.Errorf("directive missing %q; got:\n%s", want, d)
}
}
}
func TestItoa(t *testing.T) {
cases := map[int]string{0: "0", 1: "1", 9: "9", 10: "10", 42: "42",
100: "100", -1: "-1", -42: "-42"}
for in, want := range cases {
if got := itoa(in); got != want {
t.Errorf("itoa(%d) = %q, want %q", in, got, want)
}
}
}